Pressure-controlling liquid seal



Aug. 2a, 1928. 1,682,550

A. L. BROWNS PRESSURE CONTROLLING LIQUID Sm Fiied Feb. 20. 1924 Patented Aug. 28, 1928.

UNITED STATES ALFRED L. BROWNE, OF EAST ORANGE, NEW JERSEY.

PRESSURE-CONTROLLING LIQU'ID SEAL.

Application filed February 20, 1924. Serial No. 694,030.

This invention relates to pressure-controlling liquid seals. More specifically it relates to liquid seals which are adapted to maintain a predetermined difference of pressure of elastie fluid between upper ends of the legsof the seal or between the devices to which said legs are connected.

One of the objects of the invention is to provide a novel form of seal of the above mentioned class.

Another object is to provide a seal of the above mentioned class which is constructed of standard pipe and pipe fittings. Other objects and advantages will appear as the invention is hereinafter disclosed.

Referring to the drawings which illustrate what I now consider a preferred form of the invention Figs. 1, 2 and 3 are diagrammatic elevational views presented for explaining the general construction and operation of the invention.

Fig. 4 is an elevation illustrating a preferred practical embodiment of the invention.

The invention ma be employed for a number of purposes an ap lied to any one of a number of systems as wi lhereinafter appear. For the purpose of illustration and explanation I shall describe it n connection with a steam heating system comprising a steam main and a dry return 37 adapted to discharge any liquid of condensation into the boiler (not shown) through a pi e or conduit {5 39, the water line of the boiler being indicated at B.

Referring to Figs. 1, and 3, it will be seen that a liquid seal is PIOVIdGCL This seal copiprises laterally spaced vert cal legs 50, 01, connected at their lower portions by a laterally extending conduit 52. For purposes which will hereinafter appear in the dBSCllPtlOIhOf Figure 4, the legs 50, 51 are PI'OVIdQd WitlI portions which extend below the conduit 02, and the leg 51 is of greater volume (preferablv of greater cross-sectional area) than the leg 50. The legs 50, '51 are shown connected at their upper ends to the steam main 30 and the dry return 37 respectively. In this adap- ,0 tation of the invention, a valve 42 is provided,

this valve being shown connected between the u per end of the leg 51 and the dry return 37, a ove the latter. The valve 42 IS a standard form of valve adapted to permit the escape of air but to prevent the escape of water or steam from the outlet 43. V

A second conduit or connection is provided between the legs 50, 51. This conduit 53 is connected at one end to the upper end of the leg 51 and at its other end to an intermediate portion of the leg 50, the vertical distance between these points of connection depending upon the difference of elastic fluid pressure which it is desired to maintain between the main 30 and the return 37. The operation of the structure above described is substantially as follows:

)Vhcn there is no difference of pressure between the conduit 30 and 37 the level of the liquid, in the present case water, in the seal will be at the line N, hereinafter referred to as the normal liquid level of the seal. Fig. 1 illustrates this condition. rises in the conduit 30 with respect to that in the conduit .37, the liquid will be forced down in the leg and up in the leg 51 as well as the conduit 53 .(see, for example, Fig. 2). Continued increase in the difference in pressure will cause the liquid to assume the position illustrated in Fig. 3, in which the liquid seal is broken and in which elastic fluid under pressure, in the present case steam, passes from the conduit 30, through the leg 50, conduit 53,,driving' the liquid in the latter ahead of the elastic fluid and into the leg 51, or if there is'any overflow, into the pipe 39. The maximum liquid level in the leg 51, hereinafter also referred to as the maximum liquid v level of the seal, is indicated at H in Fig. 3.

The minimum liquid level in the leg 50, here inafter also referred to as the minimum liquid level of the seal, is indicated at L in Fig. 3. It will be noted that the seal is broken when the difference in pressure of elastic fluid between the conduits 30 and and 3'7 exceeds the pressure corresponding to a head of the liquid equal to the vertical distance between the levels H and L. As long as the elastic fluid pressure in the conduit 30 exceeds that in the conduit 37 by the amount equal to or greater than that represented by the head of liquid HL, the flow of elastic fluid through the conduit 53 will continue. As soon as the pressure difference drops to the predetermined amount, the liquid automatically rises in the leg 50 and again As the pressure seals the lower end of the conduit 53. In other words, the seal is self-restoring and automatically preserves or maintains a substantially constant difference of pressure between the conduits 30 and 37.

I prefer to construct my invention of standard pipe and pipe fittings as shown in Fig. 4 to which reference will now be made. The leg referred to as 50 in connection with Figs. 1, 2 and 3, is shown in Fig. 4 as consisting of two standard pipe sections 10, 11, joined by a standard T connection 13, the lower end of this leg being provided with an extension 12 ofstandard pipe joined at its upper end to the T 14 and closed at its lower by a standard cap 40.. The leg referred to as 51 in connection with Figs. 1, 2 and 3, consists of the standard pipe section 15 connected at its upper end to a standard T connection 17 and at its lower end to a standard T connection 18, the lower end ofthis leg being provided with an extension 16 connected at its upper end to the T 18 and closed at its lower end by means of a standard cap or plug 41. The laterally extending conduit referred to as 52 in connection with Figs. 1, 2 and 3, is shown in Fig.- 4 asconsisting of a standard pipe 19 connected at its opposite ends to the T connections 14 and 18. The conduit referred to as 53 in Figs. 1, 2 and 3, is shown inFig. 4 connected at its opposite ends to the T connections 17 and 13 and as comprising the following serially connected standard pipe and standard pipe fittings: close nipple 21, elbow 22, close nipple 23, right and left coupling 24, pipe 25, elbow 26 and close nipple 27. The upper end of the pipe is shown connected to a standard elbow 28 to which a standard pipe 29, leading to the conduit 30, is connected. The T17 is shown connected to the conduit 37 through the fol lowing standard fittings: close nipple 31, union 32, close nipple 33, T 34, standard-pipe 35, an elbow 38. It will be noted that the valve 42, above referred to, is connected to the T connection 34.

The operation of the device shown in Fig. 4 will be readily understood in view of the description l and explanation submited in connection with Figs. 1, 2 and 3. The various dimensions of the parts will depend upon the particular conditions of service and the predetermined pressure differential which it is desired to maintain. By way of example, assume that it is desired to employ the invention in the combination illustrated, i. e. to maintain a predetermined differential between the steam main 30 and the dry return 37. Assume further that the vertical distance between the bottom of the dry return and the boiler water line B is not less than 24 nor more than 26" and that water is employed in the seal. The following dimensions of parts may be adopted: diameter of pipe 10 diameter of pipe v25- diameter of pipe -1; length of pipe 11 between Ts 13 and 14-8; length of pipe 12 between T 14 and cap 406; and vertical distance H to L-17 Other dimensions may be satisfactorily employed depending upon the conditions of service. For example, the following dimensions of standard pipes may be employed:

Pipe 10 Pipe Pipe 15 If the vertical distance between the bottom of the dry return 37 and the boiler water line B is 27 to 33 inches the distance H to L should be 21 inches, and if the first mentioned distance is 34 or more inches, the distance H to initial cost of the parts is low and likewise the cost of replacements. Inspection is facilitated. Any dirt, sediment or solid matter will collect in the pipe sections 12 and 16 and may readily be removed by removing the detachable caps and 41. None of the pipes or fittings is surrounded b liquid so tlat corrosion is largely confine to the interiors of the various pipes and fittings.

I11 accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiments thereof, but I desire to have it understood that the apparatus disclosed is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combinations and relations described, some of these may be alteredand others omitted and some of the features of each modification may be embodied in the others without interfering with the more general results outlined, and the invention extends to such use.

What I claim is 1. A pressure-controlling liquid seal comprising in combination, an upwardly extending leg, a second upwardly extending leg, said legs consisting of standard pipe and pipe fittings, means consisting of a laterally extending standard pipe and standard pipe fittings connecting said legs below the minimum liquid level, and means consisting of standard pipe and standard pipe fittings connecting said first leg substantially at the minimum liquid level to said second leg substantially at the maximum liquid level.

2. A pressure-controlling liquid seal comprising in combination, an upwardly extendand means consisting of standard pipe and standard pipe fittings connecting said first 10 leg substantially at the minimum liquid level to said second leg substantially at the maximum liquid level.

In testimony whereof I hereto afiix my signature.

ALFRED L. BROVVNE. 

